Q.Give the uses of helium.

Step 1. Diving.

Helium mixed with oxygen is used by deep-sea divers in place of ordinary compressed air, because helium's much lower solubility in blood and body tissue (compared with nitrogen) prevents the painful and potentially fatal condition called the bends (decompression sickness), which can occur when dissolved nitrogen forms bubbles as a diver ascends.

Step 2. Welding.

Helium is used to provide a chemically inert protective atmosphere during electric-arc welding of reactive metals, preventing the hot metal from reacting with atmospheric oxygen or nitrogen while it is being welded.

Step 3. Cryogenics.

Helium has the lowest boiling point of any known substance (4.2 K), so liquid helium is used to achieve and maintain the very low temperatures needed in cryogenics and low-temperature research (for example, cooling superconducting magnets in MRI machines).

Step 4. Balloons/airships. …

List each practical use of helium together with the specific physical/chemical property (inertness, low solubility, low boiling …

Listing uses without connecting each one to the specific property responsible (e.g. saying 'used in balloons' without noting it is helium's lo …